In this comprehensive new study of human free agency, Laura Waddell Ekstrom critically surveys contemporary philosophical literature and provides a novel account of the conditions for free action. Ekstrom argues that incompatibilism concerning free will and causal determinism is true and thus the right account of the nature of free action must be indeterminist in nature. She examines a variety of libertarian approaches, ultimately defending an account relying on indeterministic causation among events and appealing to agent causation only in a reducible sense. Written in an engaging style and incorporating recent scholarship, this study is critical reading for scholars and students interested in the topics of motivation, causation, responsibility, and freedom. In broadly covering the important positions of others along with its exposition of the author's own view, "Free Will" provides both a significant scholarly contribution and a valuable text for courses in metaphysics and action theory.